Abstract: A device in which an environmental air flow is monitored by a monitoring element and in which a natural gas flow is interrupted by a shut-off element on recognition of an insufficient environmental air flow. To allow a continuous operation of the fuel cell battery the monitoring element is short-circuited by a bridging device and that its operability can thus be checked without the environmental air flow having to be interrupted. This allows a permanent operation of the fuel cell battery.

Abstract: A device in which an environmental air flow is monitored by a monitoring element and in which a natural gas flow is interrupted by a shut-off element on recognition of an insufficient environmental air flow. To allow a continuous operation of the fuel cell battery the monitoring element is short-circuited by a bridging device and that its operability can thus be checked without the environmental air flow having to be interrupted. This allows a permanent operation of the fuel cell battery.

Abstract: A lambda probe in which a measuring point for oxygen in a sensor is connected via a diffusion gap with a reaction chamber. The reaction chamber drives oxygen along the diffusion gap. A desired oxygen partial pressure is set in the reaction chamber. The pump current, which is proportional to the strength of the stream of oxygen driven along the diffusion gap, can be used as a measurement for the partial pressure of the residual oxygen in the exhaust gas during a normal operating phase. The lambda probe can be operated for test purposes intermittently in a high or low phase, in which the oxygen partial pressure in the reaction chamber is a minimum or maximum value. While changing between the operating phases, by comparing the pump currents with empirical values, conclusions with regard to the ability of the probe to function can be derived.

Abstract: A lambda probe (1) is used with the measuring apparatus for monitoring residual oxygen in an exhaust gas, in which a measuring point for oxygen in a sensor (2) is connected via a diffusion gap (22) with a reaction chamber (24). During operation of the probe the reaction chamber drives a stream of oxygen IO2 along the diffusion gap by means of a controllably adjustable oxygen partial pressure pi. By means of an electro-chemical, oxygen ion pump driven by an electrical pump current Ip, an oxygen partial pressure pi predetermined as a desired value is set in the reaction chamber. In this arrangement the pump current, the strength of which is proportional to the strength of the stream of oxygen driven along the diffusion gap, can be used as a measurement parameter for the partial pressure pm of the residual oxygen in the exhaust gas or its concentration. The residual oxygen can be monitored during a normal operating phase, the phase N.

Abstract: A lambda probe (1) is used with the measuring apparatus for monitoring residual oxygen in an exhaust gas, in which a measuring point for oxygen in a sensor (2) is connected via a diffusion gap (22) with a reaction chamber (24). During operation of the probe the reaction chamber drives a stream of oxygen IO2 along the diffusion gap by means of a controllably adjustable oxygen partial pressure pi. By means of an electro-chemical, oxygen ion pump driven by an electrical pump current Ip, an oxygen partial pressure pi predetermined as a desired value is set in the reaction chamber. In this arrangement the pump current, the strength of which is proportional to the strength of the stream of oxygen driven along the diffusion gap, can be used as a measurement parameter for the partial pressure pm of the residual oxygen in the exhaust gas or its concentration. The residual oxygen can be monitored during a normal operating phase, the phase N.

Abstract: The plant contains high temperature fuel cells which form a battery (1) in which electrochemical reactions can be carried out with a fuel (6) and a gas (5) containing oxygen while producing an electrical current (8) and a hot exhaust gas flow (7) which transports waste heat.

Abstract: The method for the operation of fuel cell battery (10) comprises a control system (14), through which the electrochemical reactions in cells (11) of the battery are influenced. Gaseous flows (1, 2) of two educts (A, B) are fed into the battery in a controlled manner in a conditionally predetermined ratio of quantities and are passed through the cells separately. The first educt (A) contains oxidizing components, the second educt (B) contains reducing components and the first educt is in particular ambient air. The educt flows (1, 2) are united after passage through the cells and are further treated by means of an afterburning process and with the production of a flow (3) of exhaust gas (C), so that at the conditionally predetermined ratio of quantities the reducing components are completely oxidized. The first educt flow, in particular the air flow, is variable through the control system to a limited extent; it is used for a regulation of the reaction temperature.

Abstract: The method for the operation of fuel cell battery (10) comprises a control system (14), through which the electrochemical reactions in cells (11) of the battery are influenced. Gaseous flows (1, 2) of two educts (A, B) are fed into the battery in a controlled manner in a conditionally predetermined ratio of quantities and are passed through the cells separately. The first educt (A) contains oxidizing components, the second educt (B) contains reducing components and the first educt is in particular ambient air. The educt flows (1, 2) are united after passage through the cells and are further treated by means of an afterburning process and with the production of a flow (3) of exhaust gas (C), so that at the conditionally predetermined ratio of quantities the reducing components are completely oxidized. The first educt flow, in particular the air flow, is variable through the control system to a limited extent; it is used for a regulation of the reaction temperature.

Abstract: The plant contains high temperature fuel cells which form a battery (1) in which electrochemical reactions can be carried out with a fuel (6) and a gas (5) containing oxygen while producing an electrical current (8) and a hot exhaust gas flow (7) which transports waste heat.

Abstract: The fuel cell module contains an integrated additional heater for a start-up operation and comprises the following components. Planar fuel cells are connected in series and form a cylindrical stack at the lateral surface of which air infeed points of the cells are located. A jacket is arranged about the cell stack and is formed as a dynamic heat insulation in a manner radially permeable to air. Furthermore, a space between the cell stack and the jacket is provided for an afterburning of gas leaving the cell and for conducting off exhaust gases. Heat sources of the additional heater are arranged at the inner surface of the jacket. During the start-up operation, the heat given off by the additional heater is at least partially introduced into the fuel cells by a radial air flow.